How Long Can Expressed Milk Be Out? Understanding Safe Storage Guidelines
Expressed breast milk can safely be left at room temperature for up to four hours. However, for optimal safety and to minimize bacterial growth, it is recommended to refrigerate or freeze the milk as soon as possible after expression.
The Importance of Safe Breast Milk Storage
Breast milk is a nutritionally complete and biologically active substance, providing vital antibodies and nutrients crucial for a baby’s healthy development. However, like any food product, breast milk can be susceptible to bacterial contamination. Following proper storage guidelines is essential to preserve its quality and protect your baby from illness. Leaving expressed milk out for too long provides an opportunity for bacteria to multiply, potentially rendering the milk unsafe for consumption.
Factors Affecting Breast Milk Storage Times
Several factors influence how long expressed breast milk can be safely stored. These include:
- Room Temperature: Warmer temperatures promote faster bacterial growth.
- Cleanliness: Thoroughly washing hands and pump parts reduces the risk of contamination.
- Initial Bacterial Load: The bacteria already present in the milk when expressed will affect its shelf life. This can be influenced by the mother’s hygiene and health.
- Stage of Lactation: Milk composition changes over time. Colostrum (early milk) has different properties than mature milk.
Recommended Breast Milk Storage Guidelines
The Centers for Disease Control and Prevention (CDC) and the Academy of Breastfeeding Medicine (ABM) provide the following guidelines for storing expressed breast milk:
| Storage Location | Optimal Time | Acceptable Time |
|---|---|---|
| Room Temperature | Up to 4 hours | Up to 6 hours |
| Refrigerator | Up to 4 days | Up to 8 days |
| Freezer | Up to 6 months | Up to 12 months |
| Deep Freezer | Up to 12 months | 12 months or more |
Important Considerations:
- “Room Temperature” refers to 77°F (25°C) or cooler.
- “Refrigerator” refers to 40°F (4°C) or cooler.
- “Freezer” refers to 0°F (-18°C) or cooler.
- Always label expressed milk with the date and time of expression.
Best Practices for Expressing and Storing Breast Milk
Here are some best practices to ensure safe and effective milk storage:
- Wash your hands thoroughly with soap and water before expressing or handling breast milk.
- Clean your breast pump parts according to the manufacturer’s instructions after each use. Sterilizing daily is also recommended, especially for younger infants.
- Use clean, food-grade containers made of glass or BPA-free plastic to store breast milk. Breast milk storage bags are also a convenient option.
- Store milk in small portions (2-4 ounces) to minimize waste.
- Cool milk quickly by placing it in the refrigerator or freezer immediately after expression.
- Thaw frozen milk in the refrigerator overnight or under cool running water. Never thaw milk at room temperature or in the microwave.
- Gently swirl thawed milk to mix any separated layers.
- Use thawed milk within 24 hours. Do not refreeze thawed milk.
- Avoid adding freshly expressed milk to already refrigerated or frozen milk. Cool the freshly expressed milk before combining it.
Common Mistakes to Avoid
- Leaving milk out for too long at room temperature. This is the most common mistake and can lead to bacterial growth.
- Storing milk in dirty containers. Contamination can compromise the safety of the milk.
- Thawing milk improperly. Thawing at room temperature or in the microwave can promote bacterial growth and destroy valuable nutrients.
- Refreezing thawed milk. Refreezing can compromise the quality and safety of the milk.
- Failing to label milk with the date and time of expression. This can lead to using milk that is past its expiration date.
Visual Cues for Spoilage
While the above guidelines are helpful, it’s also important to be able to visually identify spoiled breast milk. Signs that breast milk has gone bad include:
- Sour odor: Fresh breast milk has a slightly sweet or neutral smell.
- Chunky appearance: While separation of fat is normal, milk should not have visible clumps or curdling.
- Sour taste: Taste a small amount of the milk before feeding it to your baby.
If you notice any of these signs, discard the milk immediately. It’s always better to be safe than sorry when it comes to your baby’s health.
Impact of Freezing on Milk Nutrients
Freezing breast milk can cause some minor changes in its composition. While most nutrients remain intact, some water-soluble vitamins (like Vitamin C) may be slightly reduced. However, the overall nutritional value and immune-boosting properties of breast milk are largely preserved by freezing. Freezing is still a much better option than discarding the milk.
Frequently Asked Questions (FAQs)
Can I mix freshly expressed milk with milk that’s already been refrigerated?
No, it is best to avoid mixing freshly expressed, warm milk with already refrigerated milk. The warm milk can raise the temperature of the refrigerated milk, potentially promoting bacterial growth. Cool the freshly expressed milk in the refrigerator for about an hour before combining it with the refrigerated milk.
How long is breast milk good for after being warmed?
Warmed breast milk should be used within 2 hours. Bacteria can multiply quickly in warmed milk, so it’s best to use it promptly or discard it.
Is it safe to reheat breast milk?
It’s generally not recommended to reheat breast milk after it has been warmed and partially consumed. However, if the milk has only been warmed and not consumed, it can be refrigerated and used within 24 hours. Discard any remaining milk after that time.
What’s the best way to thaw frozen breast milk?
The best way to thaw frozen breast milk is in the refrigerator overnight. You can also thaw it under cool running water. Avoid thawing at room temperature or in the microwave, as these methods can unevenly heat the milk and destroy nutrients.
Does frozen breast milk smell different after thawing?
Yes, some mothers notice that thawed breast milk has a soapy or metallic odor. This is usually due to the breakdown of fats and is generally safe for the baby. However, if the milk smells rancid or sour, it should be discarded.
Can I use breast milk that has been stored for longer than the recommended time?
While breast milk can technically be safe to use for longer than the recommended time in the freezer (up to 12 months), its nutritional value may decrease. It’s generally best to prioritize using the oldest milk first within the recommended timeframe.
What should I do if I accidentally leave breast milk out too long?
If breast milk has been left out at room temperature for longer than 6 hours, it’s best to discard it. While it may still look and smell okay, bacteria could have multiplied to unsafe levels.
Is it safe to use breast milk that has separated?
Yes, it is perfectly normal for breast milk to separate into layers, with the fat rising to the top. Gently swirl the milk to recombine the layers before feeding it to your baby.
How do I know if my freezer is cold enough for storing breast milk?
Use a reliable freezer thermometer to ensure your freezer maintains a temperature of 0°F (-18°C) or lower.
Can I store breast milk in the door of the refrigerator?
It’s generally not recommended to store breast milk in the door of the refrigerator, as the temperature fluctuates more in the door than in the main compartment. Store milk towards the back of the refrigerator on a shelf.
What if my baby doesn’t finish the bottle of breast milk?
If your baby doesn’t finish the bottle, discard the remaining milk within 1-2 hours due to saliva contamination. Do not save it for later.
Does storing breast milk in glass or plastic containers make a difference?
Both glass and BPA-free plastic containers are safe for storing breast milk. Some mothers prefer glass because it doesn’t retain odors or stains, but plastic containers are lighter and less likely to break. The most important thing is to use clean, food-grade containers.